I am replacing new rotors and break pad on my Honda Accord 2001 EX. However, I can't open the caliper bolt.

Successfully change 1 front rotor but other Front(17mm) and one rear(14mm) is not budging at all. I tried using wd40 and waiting long enough, tried so much that now bolt has no grip. Also tried heating via Butane torch but don't want to ruin the caliper.

Anything I can do before I take it to the shop ?

Thanks - Rotor fanatic


I know your pain, I've been there before!

Firstly, buy new bolts, as even if you get that one out intact, you won't want to re-use it! When I had this problem (on a Subaru Forester), I got a kit that had new bolts, slide pins and gaiters, and replaced the lot.

You've then got a few options...

You've tried WD-40, but that's not always the best thing - you need a proper penetrating oil. Spray on, leave, repeat several times.

You can then try a tool called a 'speed wrench' - this looks a bit like an adjustable spanner, but with curved, ridged jaws - the idea is that as you try to turn it, it tightens itself up and the jaws dig into the bolt head.

If that doesn't work, the next option is a bolt extractor set. These look like a drill bit with a reverse, tapered thread - you drill a hole in the end of the bolt, insert the bit and turn it in the 'undo' direction - and as you turn, it tightens itself into the hole. I tried one of these and snapped it off in the hole!

Failing that, you're probably best cutting the head of the bolt off... Depending on the size, you might be able to use a Dremel or similar. I ended up resorting to a grinding disk in an angle grinder, and very slowly and carefully grinding down the head until it released - making sure not to cut into the caliper bracket. Once I'd got the head off, I could dismantle the assembly and was able to remove the remains of the bolt from the slider with locking pliers (though as I mentioned above, I actually used new sliders in the end, as the old ones were corroded)

In my case, it was only one bolt that wouldn't come out, as a previous repairer had used the wrong bolt - it was clearly different to all the others...

  • Quite a good list of checks and balances. I want to point out that I also tried "speed wrench" and due to it's short length, I can't get enough force to move the bolt. And on Rear caliper bolt there is not enough space to use speed wrench. But I will check for penetrating oil today and certainly don't want to cut/drill. (not feeling courageous enough) – Vaquar Jul 25 '18 at 17:24

A good quality socket and a long breaker bar has always worked for me.

If you use a long bar on cheap sockets then either the socket breaks or the bolt gets damaged ie rounded off.

Given what you describe you should consider taking it to the shop.

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